This invention relates generally to gas turbine engine rotors and, more particularly, to rotor protection systems to prevent a rotor over-speed condition.
Gas turbine engines typically include over-speed protection systems that provide rotor over-speed protection. Typically the over-speed protection systems either maintain rotor speed below critical rotor speeds or shut off fuel flow to an engine combustor. One type of known protection system receives signals indicative of rotor speed from mechanical speed sensors. The mechanical speed sensors include rotating flyweight sensing systems that indicate an over-speed condition as a result of the rotor rotating above the normal operational maximum speeds, yet below the structural failure limits. The flyweight sensing systems are hydro-mechanically coupled to a fuel bypass valve, and the fuel bypass valve reduces an amount of fuel that can be supplied to the engine if an over-speed condition is sensed.
Other types of known over-speed protection systems receive over-speed signal information from electronic control sensors. Known electronic controls derive over-speed conditions from such electronic control sensors. Such systems provide for rapid fuel shutoff and resulting engine shutdown if engine speed exceeds a normal maximum value.